What happens if you delete the snapeda footprint?
https://forum.kicad.info/t/solved-kicad-5-0-2-on-windows-cannot-import-mod-footprint/14585
jfmateos also had a problem with snapeda, and he apparently managed to solve it himself.
I’m getting a bit sleepy now, and encountered this half typed post…
DS9503 Zener diode has a simple 6-pin SMD package, but I did not see it’s measurements in the datasheet. If you know it’s measurements you can design a footprint for this component in about 2 minutes with one of KiCad’s Footprint wizards.
Bedtime, maybe more tomorrow.